[1] The unmarked accusative (sometimes called absolutive) is typically also used with a wide range of other functions that are associated with the nominative in nominative-accusative languages; they often include the subject complement and a subject moved to a more prominent place in the sentence in order to express topic or focus.
Other languages interpreted by some authors as having a marked nominative system include Igbo, Aymara and Wappo.
There may, therefore, be not a strict case system but a reflection of discourse patterns or other non-semantic parameters.
However, the Yuman language Havasupai is reported to have a purely syntactic case system, with a suffix -č marking all subjects of transitive and intransitive verbs but not of the copula; in the Nilotic language Datooga, the system is also reported to be purely syntactic.
Okinawan, a Japonic language, is generally a marked nominative language where nominative subjects are marked with the case particles ga or nu depending on their level of animacy.